I was mostly mad about not finishing. Going off the manga wasn't too bad. Plenty of other series almost completely change the manga. At least I felt that the anime was well done. I would have been mad if they had gone away from the manga and done a really bad job. It was really annoying at the end because they worked so hard to try to get to Nationals, but by the end of the series, Ryoma wasn't there and Seigaku didn't even start playing the Nationals. I'm glad they went back and made the OVAs, although I really hope that they don't finish after the Hyotei match.